The
Pec Fly is an exercise for the chest. This exercsie is meant
to isolate the pecs more with less help from the triceps as
in a chest press or push up. Make sure to keep your arms almost
straight with just a slight bend at the elbow. Bending the
elbows more will only make the exercise easier and less effective.

Starting
position: Lie on your back. Arms out to the sides with
elbows slightly bent.